2种生物炭对Pb、Cd污染土壤的修复效果

Immobilization of two biochars to Pb,Cd in contaminated soils

以污泥和发酵床废弃垫料热解制备的生物炭为钝化剂,采用土壤培养试验的BCR分级提取方法研究生物炭对铅(Pb)、镉(Cd)单一和复合污染土壤中重金属形态变化的影响。采用小白菜盆栽试验,研究添加2种生物炭对植株生物量和地上部重金属含量的影响。结果表明:添加生物炭可以促进重金属从弱酸提取态向可氧化态和残渣态转化并降低其生态风险;可以提高小白菜的生物量,其中垫料生物炭处理达到了显著性效果;能降低小白菜地上部Pb、Cd的含量,且在单一重金属污染土壤处理中达到显著性效果;与污泥生物炭相比,垫料生物炭钝化修复Pb、Cd污染土壤的效果更佳。

The biochars made from sludge and the bedding materials were added to contaminated soils to study the effects of biochars on the fractions transformation of heavy metals in lead（ Pb） and cadmium（ Cd） single and compound contaminated soil by BCR method. Potted experiment was used to assess the influence of adding biochars on the biomass and the heavy metal contents of greens. The results showed that the application of biochars promoted the transformation of the weak acid extractable Pb and Cd to oxidizable and residual fraction,and decreased the ecological risk in soils. The potted experiment results showed that adding biochars increased the biomass of greens,the bedding materials derived-biochar treatment reached significant effect,and adding biochars reduced the absorption of Pb and Cd significantly only in single contaminated soil. Compared with sludge biochar,the bedding materials derived-biochar had better effect on Pb and Cd contaminated soils.